Acoustic attenuation has become an ever increasing focus of consideration. For example, regulatory restrictions demand the increased efficiency of methods of mitigating turbo aircraft engine noise. Mechanical structures for mitigating sound, such as those which integrate honeycomb core materials, are generally known in the art. Various prior art methods of altering such honeycomb core materials for enhanced acoustic attenuation performance have included combinations of perforated sheets and honeycomb core materials. For example, multiple perforated sheets may be sandwiched between multiple sheets of a honeycomb core material for reducing sound.
In addition, laser ablation has become a widely recognized tool for processing polymer materials. With the addition of a dopant into bulk polymer materials, it is possible to sensitize most known polymers for ultraviolet and infrared ablation at selected laser wavelengths.
Important features of dopant-induced ablation are the reduction of threshold energy fluences required for ablation, and the enhancement of the etching rate by factors higher than ten.
It is therefore evident that there exists a need in the art for a method integrating polymer films with existing honeycomb core materials to achieve an acoustic attenuation structure having enhanced acoustic attenuation features.